Vibratable pattern board



VIBRATABLE PATTERN BOARD Filed June 27, 1952 INVENTORS.

fioizzzmil (ZZzkmwzd, BY Marion 0. Wilson,

United rates Patent VIBRATABLE PATTERN BOARD Bohnmil A. Zikmund, Munster, and Marion C. Wilson, Hammond, Ind, assignors to Calumet Steel Castings Corporation, Hammond, Ind, a corporation of Indiana Application June 27, 1952, Serial No. 295,896

3 Claims. (Cl. 22-56) Th present invention relates to vibratable structures and, particularly, to means for preventing damage to structures that are vibrated. The invention is especially directed to means for preventing damage to pattern boards in foundries.

In preparing a mold for metal casting in a foundry, the pattern is mounted on a board, which is usually a wooden board, and a flask is disposed about the pattern and rested on the board. Sand is then rammed into the flask to form the mold. To free the pattern from the sand without damage to the sand mold, it is necessary to vibrate the pattern board, with the flask on top thereof. To this end, it has been conventional practice to bore a hole in the end of the pattern board and to attach a conventional vibrating means or apparatus to the board by means of a bolt or the like passed through said hole and secured to the vibrator body as by a nut. During operation of the vibrator, many sharp impacts are imparted to the pattern board which results in enlargement of the hole and crushing or fracture and tearing of the portions of the board about the hole.

Attempts to eliminate the above difliculty by employing a metal washer on one side of the board have not met with success since the washer pulls through and does not prevent a bolt from attacking the side wall of the hole. After short periods of use, the side of the board around the hole is crushed and the bolt must be tightened up. This procedure is repeated and periodic tightening is necessary. Soon it becomes necessary to provide a new hole in the board for attachment of the vibrator. Ultimately, a new board is required. Obviously, this is very wasteful and expensive due to the nature and size of the boards. Furthermore, in instances wherein the patterns are formed integrally with the board, destruction of the usefulness of a board, due to fracture, tearing and extreme perforation of the end of the board, results in a loss of several hundred dollars depending upon the complexity of the pattern.

It is an object of the present invention to eliminate wasteful use of foundry pattern boards and like vibratable structures by providing means for preventing enlargement of the vibrator attachment holes and for preventing crushing, tearing and fracturing of the material around the holes.

According to the present invention, we'provide vibratable structures equipped at each vibrator attachment hole thereof with a hollow column comprising a unitary cylindrical metallic member extending through the hole in the board. Said column receives the compressive force normally delivered to the surface of the board by the vibrator and protects the walls of the hole. The column has integral continuous curved flange portions at the opposite ends thereof engaging the opposite sides of the structure and securing the column in place. The curved flanges at their free ends may be pressed into the board a slight distance. The portions of the curved flanges connected with the column portions serve to guide a bolt into said column.

2,756,471 Patented July 31, 1956 Other objects and advantages of the present invention will become apparent from the following detailed description of a preferred embodiment of the invention, wherein reference is made to the accompanying drawings, in which:

Figure 1 is a perspective view of a pattern board and a vibrator attached to one end of the board, with our invention being incorporated therein;

Figure 2 is a side view, on an enlarged scale, show ing, in cross-section, a portion of a pattern board incorporating the invention and, in elevation, a fragmentary showing of a vibrator attached thereto;

Figures 3, 4 and 5 are partial cross-sectional views of a pattern board and column showing the manner of assembly of the two; and

Figure 6 is a view similar to Figure 5 showing a modified assembly.

Referring now to the drawings, a pattern board is indicated generally at 10, the central portion of which is adapted for the reception of a pattern. Adjacent each end thereof, the pattern board is provided with a plurality of holes 12 adapted for the attachment of a vibrator 14, which is secured to the pattern bomd by suitable fastening means, such as a bolt 16 and nut 18. The vibrator 14 comprises a body defining a cylinder within which a piston is mounted for reciprocation. The vibrator is provided with a lead 20 for an air hose or the like, not shown, to induce rapid reciprocation of the piston in the cylinder. Upon reciprocation of the piston, the vibrator imparts a substantial vibration to the pattern board.

In use, a vibrator is attached to one end of the pattern board 10 and a pattern is fixedly mounted on the central portion of the board and a flask is then placed on the board about the pattern. After sand has been rammed into the flask, a conventional air control valve or the like is opened to effect actuation of the vibrators to free the pattern from the sand. The flask and sand mold are then removed from the pattern board and the pattern board is ready for the reception of another flask. As is clearly shown in Figures 2 to 6, the pattern boards may be formed of various types of wooden construction. For example, the boards may he of laminated construction, either throughout their length or at their ends where the holes 12 are located. In ordinary use, as described thus far, the vibrations imparted to the board result in enlargement of the the attachment holes 12 and crushing, fracture and tearing of the material about the holes.

To prevent damage to and destruction of the boards in the manner described, the present invention provides a hollow column, indicated generally at 22, passed through and secured to the board. The column is a unitary member comprising a cylindrical tubular portion 24 having outwardly rolled continuous flanges 26 at the opposite ends thereof. According to the present invention, the column is formed of a metal soft enough to accommodate ready rolling of the flanges without fracture of either the tubular portion or the flanges and resilient enough to receive the impacts imparted to the board without fracture or distortion. We have found aluminum alloys to be well adapted to the formation of the column. A preferred aluminum alloy consists of aluminum, and normal impurities, together with 1.2% of manganese. The alloy is so prepared that it has the following characteristics: tensile strength of about 6000 pounds per square inch; yield strength of about 60-00 pounds per square inch; shearing strength of about 11,000 pounds per square inch; endurance limit of about 7000 pounds per square inch; per cent of elongation, 30; and Brinnell hardness number 28. However, other metals having the above characteristics could serve satisfactorily.

flange 26 at one end thereof. The other end of the sleeve is not rolled or formed in any particular manner so that the column may be readily passed through a hole provided in the end of the pattern board. As is shown in Figures 3 to 5, the portion 24, which has an outer diameter substantially equal'to the diameter of the hole in the board, is passed through one of the holes 16 in the pattern board with the. one flange 26 provided on the column as originally formed engaging one surface of the board. Thereafter, a die or impact tool 28 which includes a central stem 30 and a flange rolling die face 32 has the stem 30 inserted in the tubular portion 24. The lower flange 26 is then rested on a supporting surface, which may be flat or shaped similarly to the die face 32, and an impact is imparted to the tool 28 to roll the free outer end of the tubular portion 24 outwardly to form a curved radial flange 26 engaging the opposite side of the pattern board. The flanges 26 formed as described are integral with the sleeve and are continuous throughout. The free edges of the flanges 26 may sink into the surfaces of the board a slight amount to lock the column 22 in place.

Referring to Figure 2, it will be seen that the vibrator 14 is attached to the board 10 by passing the bolt 16 through a hole in the vibrator body and through the tubular portion of the column. Preferably, a washer 34 is then applied to the'bolt and the bolt is secured in position by threading the nut 20 thereon. In use, the in bular portion 24 prevents enlargement of the hole in the pattern board, and the flanges 26 and tubular portion 24 of the column 22 prevent crushing of the surfaces of the board, without themselves being damaged.

In Figure 6, a modification of the assembly is shown which is particularly adapted for use with pattern boards and like vibratable stmctures formed of relatively soft material. In this assembly, the column 22 is identical to that described hereinbefore, but metallic washers 36 are disposed between the flanges 26 of the column and the surfaces of the board to provide additional protection for the soft material from which the board is formed.

In the foregoing, the invention has been presented as specifically applied to foundry pattern boards. It will be appreciated, however, that the invention is not so restricted in actual use and is capable of utilization in other vibratable structures.

While we have described what we regard to be a preferred embodiment of our invention, it will be appreciated that various modifications, rearrangements and changes may be made therein without departing from the scope of the present invention as defined by the appended claims.

We claim:

1. A vibratable structure comprising a wooden structure adapted to be vibrated, said structure having a vibrator attachment hole therein, and a unitary tubular metal column mounted in said hole, said column including a radial flange at each end thereof engaging opposite sides of said structure, each of said flanges being rolled radially outwardly and axially inwardly of said tubular column to present a free edge facing generally inwardly of said column and generally concentric therewith for engagement with the respective side of said structure, said rolled flanges each defining an arcuate end face on said column.

2. A pattern board comprising a wooden board adapted to mount a pattern, said board having a hole therein at one end thereof, and a unitary tubular metal column mounted in said hole, said column having a radially outwardly rolled flange at each end thereof engaging opposite sides of said board, each of said flanges being rolled radially outwardly and axially inwardly of said tubular column to present a free edge facing generally inwardly of said column and generally concentric therewith for engagement with the respective side of said board, said rolled flanges each defining a curved end face on said column, each of said flanges serving as an entrance guide for a bolt and said tubular column serv ing as a guide for the entered bolt and as a means of preventing crushing the sides of the board and enlargement of said hole, said unitary column being constructed of a metal which will permit of forming the said flanged ends Without cracking thereof.

3. In combination, a pattern board having a hole.

each end thereof engaging the opposite sides of said,

board, each of said flanges being rolled radially outwardly and axially inwardly of said tubular column to present a free edge facing generally inwardly of said column and generally concentric therewith for engagement with the respective side of said board, each of said rolled flanges defining an arcuate end face on said column, and a bolt extending through said column and adapted to extend through the hole in the vibrating member and having a nut to secure said member to said board, Said column providing a guide for said bolt and means preventing crusbing of the sides of said board and enlargement of the hole in the board, said column being constructed of a metal which will permit of forming the said flanged ends Without cracking thereof and which will receive compressive forces of vibration without permanent deformation.

References Cited in the file of this patent UNITED STATES PATENTS Re.23,743 Lambert et al. Nov. 24, 1953 52,809 Acker Feb. 27, 1866 561,190 Withers June 2, 1896 726,515 Day Apr. 28, 1903 1,225,187 Silz et a1. May 8, 1917' 1,796,394 Pickop Mar. 17, 1931 OTHER REFERENCES Modern Metals, May 1947, page 32. 

